In Season 1, about 1810, Violet shouldn't be older than 50, so born ~1760, a year before C & G wed.
Forgive me for indulging in fan fiction. The storyline they threw away...
the QC prequel & V&E stories could go like this:
QC prequel:
Lord Ledger is young (younger than Lady Danbury), dashing, new married, his wife soon to have their 1st child. She is cold & indifferent towards him, becomes evident that not just is she a snob, but she only married to Ledger because his family needed her money whereas her sharp tongue, oafishness & otherwise shrew-like manner put other suitors off. She knows her job is to produce heirs but as soon as she knew she was pg, she rebuffed him, saying they will only have children every 2 years & otherwise no conjugal relations. they bicker over name of unborn baby, he wants to name a girl child after his still-alive very kindly grandmother Violet; eventually they agree that Lady Ledger can name all the boy children as long as he gets Violet, and the boys all end up with really weird names.
after Lord Danbury's death, Ledger & Lady D. embark on a many years affair, they both feel guilty about.
V&E story set about 1777-1782: 12yo Violet is enfatuated with some other Lord's 2nd son, 18yo Edmund, he is off to be officer in American colonies campaign. They bicker, she agrees with Thomas Paine & Edmund believes utterly in Crown authority and Paine's ideas are stupid. Still, they write each other often while he is away fighting for British in colonies. Many saucy flirty letters ...
Lady D & Lord L are still having affair, Lady L seems to know & is indifferent. We viewers suddenly discover that Lady L. has many affairs with women, including her maids. Lady L may be cold to Lord L but she is fierce advocate for her children, & is responsible for telling Violet to not marry too young, hold out for a good compatible man. Debutante Violet is courted by Edmund's older brother, the presumptive future Lord Bridgerton. She entertains his proposal but then Edmund is captured by the American revolutionaries....Violet realises where her heart is, breaks off amicably with Future Lord B, who then dies suddenly, hunting accident. Edmund is recalled from duty perhaps with war wounds, to become new Lord B., tells Violet he learned more about Revolutionary cause & now agrees she was right about Paine. They reconcile & get engaged.
Meanwhile, Lady D. discovers Lady L's affairs with women, which would utterly ruin Ledger's family if it became public knowledge. Initially horrified, Lady D. comes around to being supportive, the 2 women become friends in a fashion. Lady L. comforts Lady D. when Lord L. dies suddenly and even thanks Lady D. for making her husband a happier man and therefore better husband.
The SWs better produce something better than that for V+E story.
With many fine frocks, of course.